Enabling Large Page Support in database
by satheeshkumar[ Edit ] 2012-09-20 10:11:19
Enabling Large Page Support in database ,
Some hardware/operating system architectures support memory pages greater than the default (usually 4KB). The actual implementation of this support depends on the underlying hardware and operating system. Applications that perform a lot of memory accesses may obtain performance improvements by using large pages due to reduced Translation Lookaside Buffer (TLB) misses.
In MySQL, large pages can be used by InnoDB, to allocate memory for its buffer pool and additional memory pool.
Currently, MySQL supports only the Linux implementation of large page support (which is called HugeTLB in Linux).
Before large pages can be used on Linux, the kernel must be enabled to support them and it is necessary to configure the HugeTLB memory pool. For reference, the HugeTBL API is documented in the Documentation/vm/hugetlbpage.txt file of your Linux sources.
The kernel for some recent systems such as Red Hat Enterprise Linux appear to have the large pages feature enabled by default. To check whether this is true for your kernel, use the following command and look for output lines containing “huge”:
shell> cat /proc/meminfo | grep -i huge
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 4096 kB
